Why did you and your colleagues conduct your study of women's sleep quality, sleep routines, and bedsharing and what got you interested in this fascinating topic?

A few things inspired my interest in the effects of pets on sleep. I first started thinking about this as a sleep-deprived mom of a toddler, readily acknowledging that my dogs had never interrupted my sleep the way my daughter did. Around the same time, some of my Anthrozoology students and I were reading and discussing sleep-related anthrozoological research by Bradley Smith and colleagues. They had used survey data collected by a mattress company to begin exploring ways in which pets may impact sleep. Beyond that study, there wasn’t much else published on the effects of pets on sleep. I found it intriguing that while there had been so much research published on the effects of pets on psychological well-being and physical activity, very few researchers were thinking about how pets affect our sleep. Given that we spend roughly a third of our time sleeping and given how vital sleep is to our mental and physical health, it seemed important to learn more about how pets affect our sleep.

How did you carry out your research?

At the outset of this study, we read a lot of published studies on sleep quality and the effects of human partners on human sleep. Based on our reading, we decided to conduct an online survey that included the Pittsburgh Sleep Quality Index, which is a validated, widely used measure of human sleep quality. In addition, we developed questions that asked about dogs’, cats’, and human partners’ impacts on sleep-related disturbances as well as comfort and security. We also included in our survey a number of questions regarding demographic characteristics of our participants, whether they lived with dogs and/or cats, and where those pets slept. We recruited participants primarily via social media. In addition, we asked individuals who had previously participated in our studies to complete the survey and share it with their contacts. We collected our data over the span of a few weeks during Spring 2016.

What are your main findings? It's not surprising that some mass media outlets are having a field day with your study, but I'm sure most if not all people want to know what you really learned.

Our data indicated that dogs’ sleep schedules coincided more closely with humans’ than did cats’. Among participants who shared their bed with a pet, those who slept with a dog reported their dog stayed on the bed most of the night. Those who slept with a cat reported that their cat spent less of the night on the bed. This suggests that cats may be more likely than dogs to create disruptions by moving on and off the bed during the night. In addition, we found that dog owners kept to more consistent bedtime and wake time schedules than cat owners and also tended to go to bed earlier and wake up earlier than cat owners. The degree of consistency in routine observed in dog owners may at least partially be driven by dogs needing to go outside for potty breaks shortly after waking. Dog owners may accrue some benefits by keeping to a more consistent sleep schedule. Previous research suggests people who keep to a stricter sleep routine tend to be less sleepy during the day and to be less likely to report insomnia.

Photo by Lisa Fotios from Pexels

Dogs who slept in their owners' beds were perceived to be less disruptive for sleep than human partners. At this point, we can only provide some ideas for why this may be. Further research would be needed to test these ideas, though. In comparison to human bed partners, dogs may be better at accommodating their human’s sleep schedule. It’s not uncommon for human bed partners to go to bed at very different times and wake up at very different times. Such differences in schedules can certainly disrupt sleep. It may be that dog bed partners adapt more readily to their owner’s schedule than do human bed partners.

In addition to being perceived as less disruptive than human bed partners, dog bed partners were perceived to provide more comfort and security than human bed partners. Cats were perceived to provide less comfort and security than dog or human bed partners. Again, we do not yet have concrete answers as to why participants rated dog bed partners so highly, but we have some ideas for why this may be. Some dog owners may take solace in the thought that their dog will alert them in the case of an intruder or other type of emergency; furthermore, a dog’s bark may deter a potential intruder. A cat is less likely to take on this role and so may not provide a sense of security in the same way a dog might. It would be good for future research to try to disentangle comfort-related questions from security-related ones. Although a cat is unlikely to provide the security that a dog or human partner might provide, a cat may still provide a valuable source of comfort at bedtime.

How about men and their sleep quality and routines with and without dogs or cats?

Previously published research suggests that women tend to have poorer sleep quality than men, and so that was part of our reason for focusing on females for this study. The other part was very practical: Our survey was open to male and female participants, and we just didn’t end up with enough data from male participants to run the types of analyses we could do with the female data. I definitely think it’d be worth exploring men’s perceptions about how a partner, dog, and/or cat impact their sleep!

What are some of your current and future research projects? Do you plan to continue studying similar questions?

Our research was based on individuals’ perceptions of how their pets affect their sleep; however, we often experience disruptions to our sleep that we do not recall the next morning. Therefore, it is important to take some objective measures of how dogs and cats impact human sleep. That is, we need to capture dog, cat, and human nighttime activity to get a better sense of how the activity of one individual may be impacting the activity of another. In the 1970s, Dr. Allan Hobson, who was a neurophysiologist at Harvard, collaborated with photographer Ted Spagna to place cameras over research participants’ beds and take time-lapse photos through the night to get a sense of sleep-related movements and behaviors. Fortunately, today we have activity monitoring devices that are sensitive to human and pet movement, and so we don’t have to place cameras over sleeping participants and their pets in order to better understand how pets affect our sleep. Thank goodness for that!

To that end, my research team has begun investigating dog and human resting patterns using research-grade accelerometers. We recently collaborated with Dr. Cassim Ladha at the University of Newcastle to validate an algorithm that identifies periods of rest and activity in dogs who wore accelerometers on their collars. We are building off that study to better understand dogs’ activity patterns in different housing situations.

Is there anything else you'd like to share with readers?

While participants in our study commonly reported that their dogs had positive impacts on their sleep, characteristics of individual humans and their companion animals are likely to have a big impact on whether bedsharing is ideal for an individual and their pet. For example, a dog who snores loudly or radiates heat in the middle of summer is unlikely to enhance one’s sleep quality. On the flip side, some cats may greatly enhance their owner’s sleep quality.

Thank you so much, Christy, for taking the time to answer these questions and to summarize your very interesting and important findings. I'm sure your study will attract a good deal of attention and I look forward to reading more about this line of research because so many people sleep with their companion animals and human partners and have many stories to tell.